An electric vehicle refers to an environmentally-friendly vehicle that does not discharge exhaust gas at all, and includes a high voltage battery supplying energy for driving, an inverter converting a direct current (DC) power output from the high voltage battery into an alternating current (AC) power, a driving motor for driving the vehicle by generating rotational force by receiving the AC power supplied from the inverter, and the like. The rotational power of the motor is decelerated by a decelerator and then transferred to a wheel through a driving shaft, thereby driving the electric vehicle.
Recently, an in-wheel motor vehicle in which a motor is directly embedded in a rim part of a wheel for mounting a tire to directly transfer the power of the motor to the wheel has been spotlighted, due to advantages that a power train in an intermediate stage such as a decelerator or a differential gear may be omitted to reduce a weight of the vehicle and energy loss in a power transfer process is reduced.
Meanwhile, the existing steering system for an in-wheel motor vehicle includes various complex components such as a steering shaft and column connected to a steering wheel, an electric motor providing steering toque to the steering shaft, a steering gear (rack and pinion) mounted at a lower end portion of the steering shaft, and the like, as applied in a general vehicle with an internal combustion engine, an electric vehicle, a hybrid vehicle, and the like, thereby causing deterioration in package assemblability, an increase in costs and weight, and the like.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.